Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Solid Electrolytic Capacitor for Use in High Voltage and High Temperature Applications

a technology of solid electrolytes and capacitors, which is applied in the manufacture of electrolytic capacitors, capacitor details, capacitors, etc., can solve the problems of poor stability of solid electrolytes at high temperatures

Active Publication Date: 2012-05-03
KYOCERA AVX COMPONENTS CORP
View PDF1 Cites 36 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Unfortunately, however, the stability of such solid electrolytes is poor at high temperatures due to the tendency to transform from a doped to an undoped state, or vice versa.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Solid Electrolytic Capacitor for Use in High Voltage and High Temperature Applications
  • Solid Electrolytic Capacitor for Use in High Voltage and High Temperature Applications
  • Solid Electrolytic Capacitor for Use in High Voltage and High Temperature Applications

Examples

Experimental program
Comparison scheme
Effect test

example

[0076]A tantalum anode with a size of 5.2 mm (length)×3.7 mm (width)×0.85 mm (height) was anodized at 120V in a liquid electrolyte to 10 μF, A conductive polymer coating was then formed by dipping the anode into a dispersed poly(3,4-ethylenedioxythiophene) having a solids content 1.1% (Clevios™ K, H.C. Starck). Upon coating, the part was then dried at 125° C. for 20 minutes. This process was repeated 6 times. Thereafter, the part was dipped into a dispersed poly(3,4-ethylenedioxythiophene) having a solids content 2% and dried at 125° C. for 20 minutes. Once again, this process was repeated 6 times. External carbon and silver coats were formed for finishing the manufacturing process of the anodes.

[0077]A standard copper-based leadframe was used to finish the assembly process. One portion of the leadframe was attached to the lower surface of the capacitor element with a silver adhesive. The tantalum wire of the capacitor element was then laser welded to another portion of the leadfram...

example 2

[0079]A tantalum anode with a size of 1.8 mm×2.4 mm×1.2 mm was anodized at 16V in a liquid electrolyte to 150 μF. A conductive polymer coating was then formed by dipping the anode into a butanol solution of iron (III) toluenesulfonate (Clevios™ C, H.C. Starck) for 5 minutes and consequently into 3,4-ethylenedioxythiophene (Clevios™ M, H.C. Starck) for 1 minute. After 45 minutes of polymerization, a thin layer of poly(3,4-ethylenedioxythiophene) was formed on the surface of the dielectric. The parts were washed in methanol to remove reaction by-products, anodized in a liquid electrolyte, and washed again in methanol. The polymerization cycle was repeated 12 times. The parts were then coated by graphite and silver and assembled into a ceramic housing as described in Example 1.

[0080]For life testing purposes, the parts of Examples 1 and 2 were placed in an oven at 125° C. (with an applied voltage equal to the rated voltage) and at 200° C. (with an applied voltage equal to 50% of the ra...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Diameteraaaaaaaaaa
Electric potential / voltageaaaaaaaaaa
Breakdown voltageaaaaaaaaaa
Login to View More

Abstract

A capacitor assembly for use in high voltage and high temperature environments is provided. More particularly, the capacitor assembly includes a solid electrolytic capacitor element containing an anode body, a dielectric overlying the anode, and a solid electrolyte overlying the dielectric. To help facilitate the use of the capacitor assembly in high voltage applications, it is generally desired that the solid electrolyte is formed from a dispersion of preformed conductive polymer particles. In this manner, the electrolyte may remain generally free of high energy radicals (e.g., Fe2+ or Fe3+ ions) that can lead to dielectric degradation, particularly at relatively high voltages (e.g., above about 60 volts). Furthermore, to help protect the stability of the solid electrolyte at high temperatures, the capacitor element is enclosed and hermetically sealed within a housing in the presence of a gaseous atmosphere that contains an inert gas. It is believed that the housing and inert gas atmosphere are capable of limiting the amount of oxygen and moisture supplied to the conductive polymer of the capacitor. In this manner, the solid electrolyte is less likely to undergo a reaction in high temperature environments, thus increasing the thermal stability of the capacitor assembly. In addition to functioning well in both high voltage and high temperature environments, the capacitor assembly of the present invention may also exhibit a high volumetric efficiency.

Description

BACKGROUND OF THE INVENTION[0001]Electrolytic capacitors (e.g., tantalum capacitors) are increasingly being used in the design of circuits due to their volumetric efficiency, reliability, and process compatibility. For example, one type of capacitor that has been developed is a solid electrolytic capacitor that includes an anode (e.g., tantalum), a dielectric oxide film (e.g., tantalum pentoxide, Ta2O5) formed on the anode, a solid electrolyte layer, and a cathode. The solid electrolyte layer may be formed from a conductive polymer, such as described in U.S. Pat. No. 5,457,862 to Sakata, et al., U.S. Pat. No. 5,473,503 to Sakata, et al., U.S. Pat. No. 5,729,428 to Sakata, et al., and U.S. Pat. No. 5,812,367 to Kudoh, et al. Unfortunately, however, the stability of such solid electrolytes is poor at high temperatures due to the tendency to transform from a doped to an undoped state, or vice versa. As such, a need currently exists for a solid electrolytic capacitor having improved per...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H01G9/025B82Y30/00
CPCH01G2/10H01G9/028H01G9/08H01G9/15H01G11/48Y10T29/417Y02E60/13H01G9/0032H01G9/042H01G9/052H01G9/10H01G11/56H01G2/14
Inventor VILC, LADISLAVBILER, MARTINZEDNICEK, STANISLAV
Owner KYOCERA AVX COMPONENTS CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products